Storage-battery element and method of making the same.



J. BEDDING.

STORAGE BATTERY ELEMENT km) METHOD OF MAKING THE SAME. APPucATioN FILED sun 10. 1914.

1,1 l4,31 1. Patented June 22, 1915.

J% u Zw J 4 v E 4 [P 4 ,--4'. 97 5 v U g v Jffarvre Tojul l 'ioiiom "it may) concern: a 313a it' rknown that I, JEROME Rename, a citizen of-the United Statesand a resident UNITED STATES". IPA-TE PARKER, or oston,arnsssonusnrrsg,"

' seedless-Barren nnnmnnr' Am: nnrnon ornannve ma ma; f I

of Maldenrin the county or Middlesex and :State; of Mas5achus etts,; have invented .cer-

-:-.tain new and useful Improvements'in 'Stor ing the Same,. of which the following is a' I spe a i 7 Thisiinvention age-Battery Elements and Methods of. Makas relation to electrodes orelements forlstoragegbatteries. and has =-for it's-object to. provide an electrode of max iuiumporosity, large capacity and great durability, in whichthe active material is in perfect "molecular and electrical connection with the supporting plate or grid, .is free, ,f1'on1-lead-hydrate,and is coated with subfigstantiallypure-lead suboXid. ,Accordingto my'invention, the lead is deposited-electro- 'Y fY p n the plate in avast number. of m nuteutrees. or

laments which are inter- -laced by pressure to form a. spongy filamental-y porus m'ass, through which when --==theg-electrode is, in use, there may be a tree 258;.

perdolation of -the storage battery electrolyte.

5. The figure on the accompanying drawing illustrates diagrammatically an electrolytic I cell-for the initial form'ation of the electrode, The electrodes 1 consist of perforated lead platess or, ifdesi'red light material such as I; aluminum having askin coating of lead.-

7 'anodesB-arefforzhed of'lead plates, the

surface of the anodes'and cathodes being .pret'erably equal. ,Theelectrolyte consists ofastrong' alkaline solution, preferably an aqueous solution of caustic soda, which will F bo'ilatfa temperature of say 225 F. to 235 This electrolyte should preferably be made 'of'distilledfwater and substantially ,purelcau ic soda dissolvedthrrein. In ad- ,.ditionto.,the leadanodes, I also employ supplemental anodes 3., formed of carbon. plat nuiri or-the ilike, which are arranged in a branch or. shunt Icircuit 4 controlled by a rh,eo stat;5 ,The lead anodes are in a main amate, oa;m11 d by a similar rheostat 7 kllloreor less'of the current'may be diverted throughthe two sets of anodes as may be desired according to working conditions. An

electric current of high density, say 5 am- ,presjpersquare inch (iii cathode surface is em loyed. alt-h ough thi s will fa ry .a ccord n g toconditions.. "By any suitableheating means thelelectrol-yte is heated. Dret'erahly.v

a temperature just short of the? boilmg Spe'cification of Letters Patent. v Patente Application filed m 10; 1914. Serial No. 650,691.

' point,- and the main and branchfcircuits are clos'edland controlled until there isa copious evolution of hydrogen at the electrodes *1.

At the main anodesQ, oxygen is liberated and reacting with the lead forms lead salts, probably lead sulo-oxid, lead monoxid or lead peroxid, which is. initially to someextent dissolved in the solution forming. so-

diumplumbate (N agPbO The water, the caustic soda, the lead oxids, and the' sodium plumbate are the cathodes lead-sodium alloy,.'and possibly some sodium oxid. The lead is deposite d in the form of relatively long minute trees or filaments, but

mixed all through the lead depositare prob{ ably the sodium and lead-sodium alloy,,-

Ema,

amt 22, 19.15;.

5.. probably decomposed, and on 5 are deposited lead, sodium,

though doubtless more or less of the sodium:

is hydra-ted and, does not remain as the metal. The action, which I have described,-

talies place quickly and in ashort time a thick compressible spongy mass is formed or depositedon both faces 'ofthe cathodes.

I'.regard itas important that theevolution of the oxygen at the lead anodes should not be such as to over. oxidize the lead, so as to form an'insoluble lead oxid, and hence I- employ the supplemental anodes,nsuch as platinum, carbon or the like-in order that a portion of the oxygen may not react with. the leadanodes or with the lead salts. Thus I insure to. a geaterfor less extent the formation of the lower forms of lead oxids. such as 's'uboxid or'm'onox'id. Furthermore. by 'shuntmg aportion of the current through the carbon anode, I prevent thedissolvin'g electrolyte and alsoprevent the formation of insoluble lead oxid. The evolution of the oxygen at the carbon anode may cause the formation of carbon-dioxid, and. after some time. sodium carbonate crystals may" font in the electrolyte. These, however, if formed, may be removed from timev totime and used for various purposes. -When the or an undue quantity or the lead oxid in the deposit on the cathodes has reached the desired thickness, the latter are removed and placed in a mold having many pins or projections in the top and bottom sides. and are I thereby compressed to a proper thickness without so compacting themas to destroy the spongy. or filamentary structure. -the sodium, caustic soda, etc... with which the pores are filled, all helping to preserveihe V -p010$1ty.; The compressed plates are then 1.

in a stream or bath of distilled water.

he plate is'washed until substantially all the remaining sodium, and the sodium oxid ifthere be any,are hydrated and the caustic soda thoroughlyremoved. The efiect of this --.is;to render the mass still more porous and toleave'a spon e, consisting of a structure of interlaced fi aments of chemically pure '.-lead,molecularly and electrically-connected with the base grid or support. lVh-ile the Lcompressed plates are still wet, they are dried. in an inertatmosphercg-z'. 9. containing- 'n '0'oxygen,' as in anatmosphere of pure hy- '-drogen, or of illummatinggas if desired.

1.5 To this end, theyare placed in a gently heated oven the plates are completely dry. hey are then exposed to dry air, so as to cause the fonnation'of a thin' coating of lead -'.f of the sponge causes the trees or filaments ap-"to be interlaced without destroying their I a when the plate is in the battery.

molecular connection with the plate .or grid,

- and yet leaves the mass soorous as to permit" a free percolation o --the electroljte y the exposure of the plate-thus formed to. dry air,'the surfaces formed by the filamentary structure become coated with suboxid' which does. not readily sulfate when the electrode is placed in the sulfuric acid electrolyte for use.- If the compressed plates, .while still wet, are exposed to atmospheric air, lead hydrate is formed, this being ac- 1 -"co'mpanied-by a heating of the mass. When a late so hydrated is placed in. sulfuric acid electrolyte solution for the first or ultimately causes more or less scaling on the forming charge, a considerable portion of this mixture is turned into a crystalline white sulfate which is a non-conductor and is with difliculty reduced to lead peroxid. The formation of the crystalline sulfate surface, together, with a rapid disintegration'and a loss while in use. By'my procss ess, however, the complete washing away 'ofthe sodium hydrate from the plate prekvents the formation of sodium carbonate,

and, when the moisture or water is dried ofi in an atmosphere containing no oxygen, I

prevent the formation of lead'hydrate.

" In carrying outmy process, care must be taken to so regulate the strength of the curthattliere is at all times a copious.-evo- .lution .of hydrogen at thecathodes, during.

"the formation of-the ,spg as through which'a. stream of. gas s crystalline mass, and from time to time more of the caustic solution, or of water, must be added to the electrolyte to c0mpen-' sate for losses therein. In lieu of carbon, I may employ, for the supplemental anodes, other substances, such as silver 1 or platinum if desired.

A plate,- formed in accordance with thepresent invention, possesses many advantages over a'pasted plate, which will be appreciated by one skilled inthe art, particularly in that there is no such disintegration as takes place with an amorphous 'inelastic paste and no such deterioration in capacity as is experienced therewith. claim A method of producing storage battery I plates which consists in electrolytically desupport and hydrating and removing the alkaline metal to leaye a porous spongy -mass'of lead 2: A method of producing storage battery elements which consists in passing a current of electricity through an alkaline solution containing lead salt to a cathode, to

cause an electrolytic deposit of the alkaline. metal and lead thereon, then removing andwashing the cathode, and then drying the cathode in an inert atmosphere containing no free oxygen.

3. A method of producing storage battery elements which consists in passing an electric current through. a heated strongly alkaline caustic solution containing lead salt, to a cathode, thereby decomposing said {positing lead and an alkaline metal upon a solution and said salt and. depositing lead and the alkaline metal on the cathode, washing said'cathode to remove any alkaline deposit, and drying said cathode'in an inert atmosphere.

4. A method of producing storage battery elements which consists in passing an electric current through a heated strongly alkaline caustic solution containing lead salt to a cathode, thereby decomposing said solution and said salt and depositing lead and the alkaline metal on the cathode, washing said cathode to remove any alkaline deposit, drying said cathode in an inert atmosphere,

and then suboxidizing the exposed portions of the said lead deposit on the cathode.

5. The .herein described process which consistsin passing a current of electricity through an electrolyte from a lead anode to a cathode, to cause the electrolytic deposit of lead upon said cathode, and shunting a portion of said current through an anode of other material than lead to prevent the overoxidation of the lead salt formed in the electrolyte.

6. The herein described process which consists in electrolytically depositing fila mentary non-crystalline spongy lead. upon a supporting plate, compressing the deposited lead, washing the plate and the deposit, dry-- ing said plate in an atmosphere containing no free oxygen, and then oxidizing the surfaces of the deposited lead by exposing the same to dry ai 7. The herein described method of making storage battery elements, which consists 1n electrolytically decomposing a solution of- -eaustie soda and leadoxid, depositing sodium and lead in a spongy mass upon a plate or grid, hydrating the deposited sodium and washing. away the hydrate.

8. ,The hereindes'cribed 'Inethod'of making storage battery elements, passing a eurrent ofelectrieity from a lead anode to a lead cathode through a caustic alkaline electrolyte, depositing lead and sodium on the cathode, subjecting the cathode to ,a reagent to remove'the sodium, and compressing the spongy mass thus formed onthe cathode.

The herein described method of forming a storage battery element, which consists in. electrolytically forming upon a lead surface a spongy deposit containing lead and sodium, compressing said deposit, hy- V drating and removing the sodium to increase which consists in' the porosity of the deposit, and then drying the deposited lead in an inert atmosphere.-

10. The herein described process which consists in passinga current of electricity of high density from .a lead anode to a lead cathode of substantially equal surface area through a strongly caustic-alkaline solution, shunting a portion of said current through asupplemental anode of carbon or the like to prevent over oxidation of the lead salt, then removing the. lead cathode ,'with the spongy deposit thereon, and washing the same to leave a pure leaddeposit, drying the same in an inert atmosphere, and then' oxidizing the same in dry air.

11. A storage battery element, consisting of 'a support and a porous filamentary spongy mass of pure lead thereon, the exposed surfaces of said sponge being coated with suboxid and free from lead hydrate.

1 In testimony whereof I have aflixed my signature, in presence of two witnesses.

I I JEROME BEDDING. Witnesses MARCUS 'B. MAY, P. WV. PEZZETTI. 

